U0311: Software Incompatibility With Drive Motor Control Module
What to do
Do not attempt anything under the bonnet, and have the vehicle recovered rather than persisting with it. The high-voltage system runs at several hundred volts and is not something to investigate.
Expect the car not to move at all, or to run on the engine alone if it has one.
That is the car doing the right thing, and it is worth understanding why. This code means two computers are running software that does not agree about what a torque request means. Rather than risk acting on a command it might interpret at the wrong scale — or in the wrong direction — the drive system commands no torque at all and shuts the high-voltage system down.
On a car whose motor can deliver full torque from a standstill, that is a far better answer than the alternatives. Nothing is broken.
One question worth asking yourself: has the car updated its software recently, or been part-way through an update? These systems are updated over the air more than almost anything else on a modern vehicle, and an update that only partly completed is a leading cause. If so, the fix is completing it rather than replacing anything.
Make sure it goes to a workshop equipped for high-voltage work, and tell the recovery operator what the vehicle is when you call.
What this code means
A module is running software that does not belong with the drive motor control module's. See U0300 for the family, and note that everything on this page concerns a high-voltage system that is lethal in a way nothing mechanical on a vehicle is — several hundred volts of direct current, orange cabling that is not decorative, and no part of it that a general workshop should open.
A drive motor control module is the interface between a torque request and an inverter that turns hundreds of volts into three precisely timed phases. What a given request means — its scale, its sign, the current limits that bound it, the rotor position offset that keeps the phases aligned to the magnets — is all defined in software.
Which is why the vehicle's response to a mismatch here is not graceful degradation. A drive system that cannot be certain both halves agree about torque commands the safest available value, which is none, and opens the contactors. Expect a vehicle that will not move, or that moves on the engine alone if it has one.
And that is the correct outcome rather than an inconvenience. The failure this prevents is a torque command interpreted at the wrong scale or the wrong sign — a motor delivering far more than was asked for, or driving against the direction of travel. On a vehicle whose motor can produce full torque from rest, neither is survivable to get wrong, and refusing to move is a much better answer than either.
So the practical advice is to have it recovered rather than to persist, and to send it to a workshop equipped for high-voltage work.
Where it comes from is the family's ordinary list, with one addition specific to electric drive. Motor and inverter software is updated more often than almost anything else on these vehicles, frequently over the air, so a partly-completed update is a leading cause — and the remedy is completing it rather than replacing anything.
Likely causes
Start here
- Software updated on one module only · specialist
- Interrupted module programming · specialist
- Incorrect module configuration after replacement · specialist
Less common
- Second hand module locked to another vehicle · specialist
- Software calibration out of date · specialist
- Module not coded to the vehicle · specialist
Symptoms
Components involved
Information, not instruction
CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.
Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Community experience
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